Ship building method

ABSTRACT

A procedure for building ships in which predetermined blocks of the hull are fabricated in an attitude where both the deck and the hull bottom are substantially vertical and longitudinal bulkheads and side plating are welded between the deck and the bottom along with transverse bulkheads. Following assembly of the hull block, it is transported to dockside and the bottom of the block is projected beyond the edge of the dock. Using the edge of the dock as a turning axis, the block is rotated to position the bottom of the block lowermost and the deck uppermost. The rotation of the hull block is preferably accomplished by elevating the block adjacent the deck by a hydraulic cylinder. Simultaneously the bottom of the hull block is lowered by hydraulic cylinders. A swing table may be used to support the hull block during such rotation, the table being pivoted to the edge of the dock.

United States Patent Maeda SHIP BUILDING METHOD [72] Inventor: KazuoMaeda, Chiba, Japan [73] Assignee: Mitsui Shipbuilding and EngineeringCo. Ltd., Tokyo, Japan 22 Filed: Jan. 12, 1971 21 Appl.N0.: 105,870

[30] Foreign Application Priority Data Sept. 4, 1970 1 Japan ..45/77564[52] U.S.Cl. ..114/77R,2I4/l Q,214/l52 [51 Int. Cl. .363!) 3/02 [58]Field of Search...2l4/130 R, 10,1 H,l52,lR; 114/65, 65 A, 77, 77 A [1513,698,344 [451 .Oct. 17, 1972 Primary Examiner-Gerald M. ForlenzaAssistant Examiner-Frank E. Werner Attorney-Howson and Howson 57ABSTRACT A procedure for building ships in which predetermined blocks ofthe hull are fabricated in an attitude where both the deck and the hullbottom are substantially vertical and longitudinal bulkheads and'sideplating are welded between the deck and the bottom 7 along withtransverse bulkheads. Following assembly of the hull block, it istransported to dockside and the bottom of the block is projected beyondthe edge of the-dock. Using the edge of the dock as a turning axis, theblock is rotated to position the bottom of the block lowermost and thedeck uppermost. The rotation of the hull block is preferablyaccomplished by elevating the block adjacent the deck by a hydrauliccylinder. Simultaneously the bottom of the hull block is lowered byhydraulic cylinders. A swing table may be used to support the hull blockduring such rotation,

the table being pivoted to the edge of the dock.

4-Claims, 2 Drawing Figures i Y\ n SHIP BUILDING METHOD The presentinvention relates to a method of building a ship from a plurality offabricated hull blocks including the step of transferring eachfabricated block to a dock for assembly with other blocks to form thehull.

Heretofore, the fabricated block is constructed and transferred to thedock in the normal attitude. The transferring of the fabricated blockbecomes increasingly difficult and dangerous as the scale of the blockincreases.

Therefore, an object of the present invention is to provide a noveltransferring method which may be performed safely and easily.

The present invention will be understood from the following descriptiontaken in connection with the accompanying drawings in which:

FIG. 1 is a perspective view showing constructing a fabricated hullblock; and

FIG. 2 is a sectional view showing rotating the fabricated block.

Referring to the drawings and more particularly to FIG. 1, in the priorart, the fabricated hull block has been constructed in such a way that alongitudinal bulkhead 2, side plating 3 and transverse bulkhead 4 areerected and fixed to the bottom structure 1 placed on the base and thena deck plate 5 is fixed thereon. This method requires much weldingworking at high position or in the upward looking posture. Theseworkings tend to be difficult and dangerous and the tendency increasesas the block becomes larger. If the transverse bulkhead 4 is placed onthe base as shown in FIG. 1 and the longitudinal bulkhead 2, sideplating 3, bottom structure 1 and deck plate 5 are secured to thetransverse bulkhead, a relatively lower position of the block may beobtained. In addition if the block is rotated about an upright axis ofthe hull block, such as the line X-X connecting the deck plate and thebottom structure, all of the welding working can be performed in thedownward looking posture, i.e. at or below the eye level.

However, since the fabricated block can not be as sembled into a hull insuch an attitude, the block must be rotated to the normal attitude. Inaccordance with the present invention, the fabricated block istransfered to the side of the dock with keeping the line X-X inhorizontal as shown in FIG. 2. It is noted that the edge of the dock isat ground level and the bottom of the dock is below the level of theedge. Owing to such an attitude, the fabricated block is stable duringtransferring, which results in safety and facility during such handling.At the side of the dock 6 a swing table 7 is mounted for rotation abouta axis 8. A hydraulic hoisting device 9 is provided at ground levelunder one end of the swing table 7 and suitable number of hydrauliccylinder 10 are provided in the bottom of the dock under the other endof the table.

The fabricated block 12 is put on the swing table 7 so that the hullbottom projects beyond the edge of the dock, and the table is thenrotated in the anti-clockwise direction by the hoisting device 9. Therods 11 of the hydraulic cylinders 10 are progressively lowered whilekeeping the contact with the swing table 7 as shown by dotted line inFIG. 2. Thus the fabricated block may be stood on the bottom of the dockin the normal attitude in which the upright axis of the hull issubstantially vertical. The erected block is transfered to the positionwhere a hull is assembled.

The above described swing table is not always necessary. It wouldbepossible to provide rollers at the side edge of the dock in order torotate and guide the fabricated block. Cranes may be also used forrotating the fabricated block.

Thus in accordance with the present invention, the fabricated block maybe easily-rotated without necessity of great power, because the rotationis performed along the side edge of the dock. Further, the fabricatedblock may be safely and easily transfered while keeping the aforesaidupright axis connecting the deck plate and the bottom structurehorizontal.

What is claimed is:

1. A method of building a ship hull by assembling a plurality offabricated hull blocks, comprising the steps of transferring thefabricated blocks to the side of a dock having a side edge elevatedabove the dock bottom while keeping horizontal an upright axis of theblock connecting the deck plate and the bottom structure, projecting thebottom structure of the block beyond the edge of the dock above the dockbottom, and standing the fabricated block to erect the upright axis ofthe hull block to its normal attitude by rotating the fabricated blockabout an axis at the side edge of the dock, lowering the bottomstructure down to the dock bottom.

2. A method according to claim 1 wherein said block is fabricated withthe said upright axis horizontal, in-

cluding the step of rotating said block during fabrication so thatsubstantially all welding operations are performed at or below eyelevel.

3. A method according to claim 1 including the step of supporting saidhull block by a swing table pivoted to the dock edge during saidrotation of the fabricated block.

4. A method according to claim 1 including the step of providinghydraulic supports for the bottom structure and lowering said supportsduring said rotation concurrently with raising the deck.

1. A method of building a ship hull by assembling a plurality offabricated hull blocks, comprising the steps of transferring thefabricated blocks to the side of a dock having a side edge elevatedabove the dock bottom while keeping horizontal an upright axis of theblock connecting the deck plate and the bottom structure, projecting thebottom structure of the block beyond the edge of the dock above the dockbottom, and standing the fabricated block to erect the upright axis ofthe hull block to its normal attitude by rotating the fabricated blockabout an axis at the side edge of the dock, lowering the bottomstructure down to the dock bottom.
 2. A method according to claim 1wherein said block is fabricated with the said upright axis horizontal,including the step of rotating said block during fabrication so thatsubstantially all welding operations are performed at or below eyelevel.
 3. A method according to claim 1 including the step of supportingsaid hull block by a swing table pivoted to the dock edge during saidrotation of the fabricated block.
 4. A method according to claim 1including the step of providing hydraulic supports for the bottomstructure and lowering said supports during said rotation concurrentlywith raising the deck.